Field of the Invention
The present invention relates to a water jacket for a cylinder block. More particularly, the present invention relates to a water jacket for a cylinder that may improve overall cooling efficiency of the cylinder block by controlling coolant flow inside the cylinder block.
Description of Related Art
Generally, some of heat generated in a combustion chamber of an engine is absorbed by a cylinder head, a cylinder block, intake and exhaust valves, a piston, etc.
When temperatures of the constituent components of the engine excessively increase, the constituent components may be thermally deformed, or an oil film of an inner wall of a cylinder may be damaged such that lubrication performance deteriorates, resulting in thermal problems of the engine.
Due to the thermal problems of the engine, abnormal combustion such as combustion failure, knocking, etc. occurs, thus a piston may be melted, which may result in serious damage to the engine. Further, thermal efficiency and power of the engine may deteriorate. In contrast, excessive cooling of the engine may cause the power and fuel consumption to deteriorate, and may cause low temperature abrasion of the cylinder, thus it is necessary to appropriately control temperature of the coolant.
In this respect, in a typical engine, a water jacket is provided inside a cylinder block and a cylinder head, and a coolant circulating in the water jacket cools a periphery of a spark plug corresponding to a combustion chamber and metal surfaces such as peripheries of an exhaust port, a valve seat, etc.
However, in the typical engine, since the coolant flowing in according to the order of cylinders is sequentially circulated in the water jacket provided in the cylinder block, portions of the cylinder block corresponding to upper and lower portions of the combustion chamber at which a relative temperature difference is generated are not effectively cooled, such that the engine is not entirely fully cooled.
In addition, durability of the engine deteriorates due to the poor cooling efficiency of the engine, and if a separate cooling jet is provided and a high performance water pump is used in order to prevent the deterioration of the durability of the engine, costs thereof may increase.
Further, when the temperature of the coolant is low, viscosity of engine oil is high, thus as frictional force increases, fuel consumption increases, that is, fuel efficiency deteriorates, while when the coolant temperature is excessively high, since knocking occurs, performance of the engine may deteriorate by adjusting ignition timing in order to suppress the knocking.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.